WO2008072812A1

WO2008072812A1 - Mechanism spring and swash plate type compressor employing the same

Info

Publication number: WO2008072812A1
Application number: PCT/KR2006/005471
Authority: WO
Inventors: Geonho Lee; Haksoo Kim; Kibeom Kim; Ikseo Park; Kijung An; Peter Giese; Frank Obrist; Christian Schmaelzle
Original assignee: Doowon Technical College; Doowon Electronic Co., Ltd.; Obrist Engineering Gmbh
Priority date: 2006-12-14
Filing date: 2006-12-14
Publication date: 2008-06-19
Also published as: KR101074933B1; KR20090087925A

Abstract

Provided are a mechanism spring and a swash plate type compressor employing the same. The mechanism spring includes: a flat part having an insert groove formed at one side and into which a drive shaft is inserted, and two extension plates formed at both sides of the insert groove; a curved support part having two support plates disposed opposite to the two extension plates of the flat part, and bent toward the flat part in a convex manner when seen from a side view; and a curved connection part having two curved connection plates for connecting one ends of the two extension plates of the flat part to one ends of the two support plates of the curved support part. Therefore, it is possible to improve initial working performance of a compressor driven at a minimum inclination angle during operation of an air conditioner, and readily absorb shock due to rapid variation to the minimum inclination angle of the swash plate in a compression process during non-operation of the air conditioner. In addition, it is possible to readily perform their assembly and simplify the structure. Further, it is possible to prevent friction noise due to slide contact during operation of the compressor by securely fixing the mechanism spring to the drive shaft.

Description

MECHANISM SPRING AND SWASH PLATE TYPE COMPRESSOR EMPLOYING THE SAME

Technical Field

[1] The present invention relates to a mechanism spring and a swash plate type compressor employing the same, and more particularly, to a mechanism spring and a swash plate type compressor employing the same capable of improving initial working performance (an initial compression process) of the compressor driven at a minimum inclination angle (zero degree) during operation of an air conditioner, and absorbing shock due to rapid variation to the minimum inclination angle (zero degree) of the swash plate in a compression process during non-operation of the air conditioner.

[2]

Background Art

[3] As is well known, a general swash plate type compressor, widely used as a compressor for an air conditioner of an automobile, has a disc-shaped swash plate installed at a drive shaft for receiving power from an engine to vary in inclination as it rotates, and a plurality of pistons slidably installed at an outer periphery of the swash plate by shoes. The pistons reciprocally move in a plurality of cylinder bores formed in a cylinder block to suck a coolant gas, compress the coolant gas, and discharge the coolant gas.

[4] Recently, a variable displacement swash plate type compressor has been widely proposed to obtain precise movement control by varying an inclination angle of the swash plate depending on variation of thermal load to control strokes of the pistons, and simultaneously reduce rapid torque variation of an engine due to the compressor, thereby improving driving quality of an automobile.

[5] FIG. 1 illustrates a variable displacement swash plate type compressor disclosed in

Korean Patent Application No. 1999-21935, which will be described in detail below.

[6] The conventional variable displacement swash plate type compressor 10 includes a cylinder block 11 having a plurality of cylinder bores 11a arranged in parallel in a longitudinal direction at its inner periphery, a front housing 12 sealed in the front of the cylinder block 11, and a rear housing 13 sealed in the rear of the cylinder block 11 with a valve plate 13a interposed therebetween.

[7] A swash plate chamber 14 is formed inside the front housing 12. One end of a drive shaft 15 passing through the swash plate chamber 14 is rotatably supported at the center of the front housing 12, and the other end of the drive shaft 15 is supported by a bearing 1 Ic at a center shaft hole 1 Ib in the cylinder block 11. [8] In addition, the drive shaft 15 includes a lug plate 16 press fitted thereinto in a spaced-apart manner, a varying-inclination swash plate 17 through which the drive shaft 15 passes, and a spring 27 installed between the lug plate 16 and the swash plate 17, resiliently supporting the swash plate 17 against the lug plate 16. A minimum inclination angle of the swash plate 17 for compressing coolant can be maintained by the spring 27.

[9] When the minimum inclination angle of the swash plate 17 is not maintained, even though the drive shaft 15 rotates in initial operation of the compressor, there is no compression of the coolant. As a result, the initial operation of the compressor is unstable, and initial load is too high.

[10] A pair of power transmission projections 16a each having a hinge hole 16b formed straight therethrough integrally project from one end of one surface of the lug plate 16 to be rotated together with the drive shaft 15.

[11] The swash plate 17 is inserted into the drive shaft 15 at a predetermined angle, and a hinge pin 18 fixed to the swash plate 17 is inserted into a hinge hole 16b formed at the power transmission projection 16a of the lug plate 16 such that the swash plate 17 rotates together with the lug plate 16, causing it to vary in inclination.

[12] In addition, an outer periphery of the swash plate 17 is slidably installed via shoes

20 into pistons 19 which are installed in the cylinder bores 11a.

[13] Since the swash plate 17 is rotated in a tilted state, the pistons 19 into which the outer periphery is inserted via the shoes 20 reciprocate in the cylinder bores 1 Ia of the cylinder block 11.

[14] In addition, the rear housing 13 has a suction chamber 21 and a discharge chamber

22, and the valve plate 13a interposed between the rear housing 13 and the cylinder block 11 has suction ports 23 and discharge ports 24 corresponding to the cylinder bores 11a.

[15] The suction ports 23 and the discharge ports 24 formed at the valve plate 13a have suction valves 25 and discharge valves 26 which open and close the suction ports 23 and the discharge ports 24 in response to pressure variation caused by reciprocation of the pistons 19.

[16] In addition, the rear housing 13 includes a control valve 28 for linking the swash plate chamber 14 and the suction chamber 21 such that a difference between a coolant suction pressure in the cylinder bore 11a and a pressure in the swash plate chamber 14 is varied to adjust the inclination of the swash plate 17.

[17] The conventional variable displacement swash plate type compressor 10 adjusts the inclination of the swash plate 17 in response to a difference between a pressure in the swash plate chamber 14 and a suction pressure in the cylinder bores 11a. The inclination of the swash plate 17, in turn, determines the length of the strokes of the pistons 19 connected to the swash plate 17, which determines the discharge capacity of the compressor.

[18] As described above, the conventional swash plate type compressor has a structure maintaining a minimum inclination angle using a coil spring 27.

[19] As a result, initial working performance of the compressor driven at a minimum inclination angle during operation of an air conditioner may be somewhat insufficient, and the inclination angle of the swash plate during a compression process may be abruptly changed to the minimum inclination angle in non-operation of the compressor.

[20] In particularly, since the spring 27 is interposed between the lug plate 16 and the swash plate 17, an assembly process with the drive shaft is troublesome, and its structure is also complicated.

[21] In addition, the spring 27 may be slipped between the lug plate 16 and the swash plate 17 when the lug plate 16 and the swash plate 17 are rotated by the drive shaft 15, thereby generating noise during operation. Disclosure of Invention Technical Problem

[22] An object of the present invention is to provide a mechanism spring and a swash plate type compressor employing the same capable of improving initial working performance of the compressor driven at a minimum inclination angle during operation of an air conditioner, and absorbing shock due to rapid variation to the minimum inclination angle of the swash plate in a compression process during non-operation of the air conditioner.

[23] Another object of the present invention is to provide a mechanism spring and a swash plate type compressor employing the same capable of readily performing assembly and obtaining simple structure.

[24] Still another object of the present invention is to provide a mechanism spring and a swash plate type compressor employing the same capable of preventing friction noise due to slide contact on operation by securely fixing the mechanism spring to a drive shaft.

[25]

Technical Solution

[26] An aspect of the invention provides a mechanism spring clipped onto a drive shaft of a swash plate type compressor to maintain a minimum inclination angle, comprising: a flat part having an insert groove formed at one side and into which a drive shaft is inserted, and two extension plates formed at both sides of the insert groove; a curved support part having two support plates disposed opposite to the two extension plates of the flat part, and bent toward the flat part in a convex manner when seen from a side view; and a curved connection part having two curved connection plates for connecting one ends of the two extension plates of the flat part to one ends of the two support plates of the curved support part.

[27] In this process, inner surfaces of the two extension plates forming the insert groove of the flat part may be disposed parallel to each other.

[28] In addition, hooking pieces may project from the inner surfaces of the two extension plates, corresponding to an inlet of the insert groove of the flat part, to be disposed opposite to each other.

[29] Further, through-holes may be formed adjacent to the hooking pieces of the flat part.

[30] Furthermore, the support plate may have a width in which narrows toward the other end of the curved support part.

[31] Another aspect of the invention provides a swash plate type compressor including: a cylinder block having a plurality of cylinder bores; a housing having a swash plate chamber, and a suction chamber and a discharge chamber in communication with the cylinder bores through suction/discharge valves; a drive shaft rotatably supported by the cylinder block and the housing; a swash plate installed at the drive shaft to vary in inclination; a spring installed at the drive shaft to resiliently support the swash plate; and pistons slidably engaged with the swash plate and reciprocally accommodated in the cylinder bores, characterized in that the spring is the mechanism spring described above and installed at the drive shaft such that a tip of a curved support part of the mechanism spring is in contact with the swash plate when the swash plate is inclined at a minimum inclination angle.

[32] Still another aspect of the invention provides a swash plate type compressor including: a cylinder block having a plurality of cylinder bores; a housing having a swash plate chamber, and a suction chamber and a discharge chamber in communication with the cylinder bores through suction/discharge valves; a drive shaft rotatably supported by the cylinder block and the housing; a swash plate installed at the drive shaft to vary in inclination; a link connecting the swash plate with the drive shaft; a spring installed at the drive shaft to resiliently support the swash plate; and pistons slidably engaged with the swash plate and reciprocally accommodated in the cylinder bores, characterized in that the spring is the mechanism spring described above and installed at the drive shaft such that a tip of a curved support part of the mechanism spring is in contact with the swash plate or the connection link when the swash plate is inclined at a minimum inclination angle.

[33] In this case, the drive shaft may have coupling grooves formed at both sides thereof in a circumferential direction to be inserted inside inner surfaces of two extension plates of a flat part of the mechanism spring. [34] In addition, when the two extension plates are inserted into the drive shaft, the two hooking pieces may resiliently ride over the drive shaft to be hooked by the coupling grooves. [35]

Brief Description of the Drawings [36] The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: [37] FIG. 1 is a longitudinal cross-sectional view of a conventional swash plate type compressor; [38] FIG. 2 is a longitudinal cross-sectional view of a swash plate type compressor in accordance with an exemplary embodiment of the present invention;

[39] FIG. 3 is an assembly perspective view of a mechanism spring and a drive shaft;

[40] FIG. 4 is a perspective view of the mechanism spring of FIG. 3;

[41] FIG. 5 is an exploded perspective view of FIG. 3; and

[42] FIG. 6 is a longitudinal cross-sectional view of a swash plate type compressor in accordance with another exemplary embodiment of the present invention. [43]

Best Mode for Carrying Out the Invention [44] Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. [45] FIGS. 2 to 5 illustrate a swash plate type compressor, and a mechanism spring clipped onto a drive shaft of the swash plate type compressor. [46] As shown, a swash plate type reciprocating compressor 1000 in accordance with an exemplary embodiment of the present invention includes a housing 100, a cylinder block 110 having a plurality of cylinder bores 110a, a drive shaft 140 rotatably supported by the cylinder block 110, a swash plate 150 connected to the drive shaft

140 and installed to vary in inclination as it rotates, pistons 200 accommodated in the cylinder bores 110a and capable of sliding back and forth with respect to the swash plate 150, a suction/discharge valve apparatus 300 installed opposite to a bottom surface of the piston 200, and a suction chamber 131 and a discharge chamber 132 formed at the housing 100 and separated by the suction/discharge valve apparatus 300. [47] The housing 100 comprises a front housing 120 and a rear housing 130 with the cylinder block 110 interposed therebetween. [48] In addition, the rear housing 130 has a suction chamber 131 and a discharge chamber 132. A valve plate 330 has suction ports 331 for communicating the cylinder bores 110a with the suction chamber 131, and discharge ports 332 for communicating the cylinder bores 110a with the discharge chamber 132.

[49] Further, the suction ports 331 and the discharge ports 332 formed at the valve plate

330 include suction valves and discharge valves for opening and closing the suction ports 331 and the discharge ports 332 in response to pressure variation caused by reciprocation of the pistons 200, respectively.

[50] The cylinder block 110 has eight cylinder bores 110a. Coolant introduced from the suction chamber 131 by the pistons 200 reciprocating through the cylinder bores 110a is continuously compressed. Of course, the number of the cylinder bores 110a may be varied.

[51] The drive shaft 140 is rotatably supported by the front housing 120 and the cylinder block 110 via a bearing 400.

[52] Further, the swash plate 150 is slidably coupled with the pistons 200 via shoes 201.

[53] Furthermore, the swash plate 150 has connection projections 155 formed at its front and rear parts. Connection links 600 are interposed between the connection projections 155 and the drive shaft 140, which are connected to each other by hinge pins 610. Therefore, the connection links 600 and the connection projections 155, and the connection links 600 and the drive shaft 140, can be hinged to each other.

[54] Meanwhile, as shown in FIGS. 3 and 4, a mechanism spring 160 for maintaining a minimum inclination angle of the swash plate 150 is installed at the drive shaft 140.

[55] The mechanism spring 160 is formed of a plate member and bent in various radii of curvature. Especially, when the mechanism spring 160 is deployed, the mechanism spring 160 has an elongated groove to be clipped onto the drive shaft 140.

[56] Hereinafter, the structure of the mechanism spring 160 will be described in detail with reference to the completed structure.

[57] As shown in FIG. 5, the mechanism spring 160 generally includes a flat part 161, a curved support part 162 disposed opposite to the flat part 161, and a curved connection part 163 for connecting the curved support part 162 and the flat part 161, which form an appropriately R shape when seen from a side view.

[58] While the mechanism spring 160 has a complicate structure, in order to prevent the mechanism spring 160 from leaning due to eccentricity during rotation, the mechanism spring 160 should have the same center of gravity G as the drive shaft 140, when seen from a side view.

[59] Specifically, the flat part 161 has an insert groove 161a formed at one side thereof and directly clipped onto the drive shaft 140, and two extension plates 161b formed at both sides of the insert groove 161a.

[60] In this case, inner surfaces of the two extension parts 161b forming the insert groove 161a of the flat part 161 may be disposed parallel to each other. When the two extension plates 161b are actually coupled with the drive shaft 140, the inner surfaces of the extension plates 161b are closely fitted into coupling grooves 144 formed around the drive shaft 140.

[61] In addition, hooking pieces 161c project from the inner surfaces of the two extension plates 161b, corresponding to an inlet of the insert groove 161a of the flat part 161, to be disposed opposite to each other. When the two extension plates 161b are fastened to the drive shaft 140, since the two hooking pieces 161c resiliently ride over the drive shaft 140, it is possible to prevent the spring from being separated from the drive shaft 140 after assembly.

[62] Further, through-holes 161d are formed adjacent to the hooking pieces 161c of the flat part 161. Therefore, when the hooking pieces 161c ride over the drive shaft 140, and the mechanism spring 160 can be smoother coupled with the drive shaft 140 due to increased elasticity.

[63] The curved support part 162 is constituted of two support plates 162a disposed opposite to the two extension plates 161b of the flat part 161 to be bent toward the flat part 161 in a convex manner, when seen from a side view. That is, the flat part 161 and the curved support part 162 have a relationship in which a space therebetween widens, narrows, and then widens again from their connection point.

[64] In this process, each of the support plates 162a has a width in which narrows toward its tip to reduce a contact area between the support plates 162a and the swash plate or the connection link, thereby preventing interference with ambient structures.

[65] In addition, the curved connection part 163 has two curved connection plates 163a connecting one ends of the two extension plates 161b of the flat part 161 and one ends of the two support plates 162a of the curved support part 162. When seen from a side view, the curved connection part 163 may have an arcuate shape, not limited thereto.

[66] Therefore, the mechanism spring 160 is securely clipped onto the drive shaft 140 to be rotated together with the drive shaft 140.

[67] When the mechanism spring 160 is assembled to the drive shaft 140, the curved connection part 163 is first inserted around the drive shaft 140, and then the inner surfaces of the two extension plates 161b of the flat part 161 are coupled with the coupling grooves 144 of the drive shaft 140.

[68] In this case, since the hooking pieces 161c projecting from the inner surfaces of the extension plates 161b resiliently ride over the coupling grooves 144 of the drive shaft 140, it is possible to prevent the mechanism spring 160 from being separated from the drive shaft 140.

[69] Therefore, when the swash plate 150 is at a minimum inclination angle, the tips of the support plates 162a of the mechanism spring 160 are in resilient contact with the swash plate 150 or the connection links 600 to resiliently maintain the minimum in- clination angle of the swash plate 150.

[70] FIG. 6 illustrates a mechanism spring installed in the conventional swash plate type compressor of FIG. 1. Since surrounding structure has been described hereinbefore, the same description as the above will not be repeated.

[71] As shown, the mechanism spring in accordance with the present invention is securely clipped onto the drive shaft of the compressor to maintain the minimum inclination angle.

[72]

Industrial Applicability

[73] As can be seen from the foregoing, since a mechanism spring has a plate shape rather than a coil shape, it is possible to improve initial working performance of a compressor driven at a minimum inclination angle during operation of an air conditioner, and readily absorb shock due to rapid variation to the minimum inclination angle of the swash plate in a compression process during non-operation of the air conditioner.

[74] In addition, since the drive shaft has coupling grooves formed in its circumferential direction and the spring is assembled onto the coupling grooves, assembly is very easy and the structure is very simple.

[75] Further, since the drive shaft and the mechanism spring are securely coupled with each other by fastening the extension plates and the hooking pieces of the flat part to the coupling grooves of the drive shaft, it is possible to prevent friction noise due to slide contact during operation of the compressor.

[76] Although a few embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

[77]

Claims

[1] A mechanism spring clipped onto a drive shaft of a swash plate type compressor to maintain a minimum inclination angle, comprising: a flat part having an insert groove formed at one side and into which a drive shaft is inserted, and two extension plates formed at both sides of the insert groove; a curved support part having two support plates disposed opposite to the two extension plates of the flat part, and bent toward the flat part in a convex manner when seen from a side view; and a curved connection part having two curved connection plates for connecting one ends of the two extension plates of the flat part to one ends of the two support plates of the curved support part.

[2] The mechanism spring according to claim 1, wherein inner surfaces of the two extension plates forming the insert groove of the flat part are disposed parallel to each other.

[3] The mechanism spring according to claim 2, wherein hooking pieces project from the inner surfaces of the two extension plates, corresponding to an inlet of the insert groove of the flat part, to be disposed opposite to each other.

[4] The mechanism spring according to claim 3, wherein through-holes are formed adjacent to the hooking pieces of the flat part.

[5] The mechanism spring according to claim 3, wherein the support plate has a width in which narrows toward the other end of the curved support part.

[6] The mechanism spring according to claim 1, wherein the mechanism spring has the same center of gravity as an axial center of the drive shaft when seen from a side view.

[7] A swash plate type compressor comprising: a cylinder block having a plurality of cylinder bores; a housing having a swash plate chamber, and a suction chamber and a discharge chamber in communication with the cylinder bores through suction/discharge valves; a drive shaft rotatably supported by the cylinder block and the housing; a swash plate installed at the drive shaft to vary in inclination; a spring installed at the drive shaft to resiliently support the swash plate; and pistons slidably engaged with the swash plate and reciprocally accommodated in the cylinder bores, characterized in that the spring is the mechanism spring of any one of claims 1 to 6 and installed at the drive shaft such that a tip of a curved support part of the mechanism spring is in contact with the swash plate when the swash plate is inclined at a minimum inclination angle.

[8] A swash plate type compressor comprising: a cylinder block having a plurality of cylinder bores; a housing having a swash plate chamber, and a suction chamber and a discharge chamber in communication with the cylinder bores through suction/discharge valves; a drive shaft rotatably supported by the cylinder block and the housing; a swash plate installed at the drive shaft to vary in inclination; a link connecting the swash plate with the drive shaft; a spring installed at the drive shaft to resiliently support the swash plate; and pistons slidably engaged with the swash plate and reciprocally accommodated in the cylinder bores, characterized in that the spring is the mechanism spring of any one of claims 1 to 6 and installed at the drive shaft such that a tip of a curved support part of the mechanism spring is in contact with the swash plate or the connection link when the swash plate is inclined at a minimum inclination angle.

[9] The swash plate type compressor according to claim 7 or 8, wherein the drive shaft has coupling grooves formed at both sides thereof in a circumferential direction to be inserted inside inner surfaces of two extension plates of a flat part of the mechanism spring.

[10] The swash plate type compressor according to claim 9, wherein, when the two extension plates are inserted into the drive shaft, the two hooking pieces resiliently ride over the drive shaft to be hooked by the coupling grooves.